Add isIsolated parameter to MarginLoanService and MarginRepayService (#268)
Add isIsolated parameter to MarginLoanService and MarginRepayService (#268)

* Add isIsolated parameter to MarginLoanService and MarginRepayService

* fix parameter name

* pass the symbol as a parameter

* update doc

Co-authored-by: Jeremy Pansier <aab7a998c1bf79eb5e1736b76e8370e33b167e1d@olea-medical.com>
adshao/go-binance